Prewetted medical wipe with impermeable barrier

ABSTRACT

A wetted, disposable wipe constructed by bonding a layer of absorbent material to one side of a barrier sheet that is impermeable to infectious agents and insoluble in dermatological fluids, filling a reservoir in the barrier with a dermatological fluid, and hermetically sealing the absorbent layer between the barrier and a cover. The peripheral edges of the absorbent layer are spaced inwardly from the peripheral edges of the barrier to provide a surrounding zone of the impermeable barrier alone. The absorbent layer bond to the barrier is resistant to degradation caused by exposure to the dermatological fluid. The cover is secured by an adhesive that is resistant to degradation caused by exposure to the dermatological fluid and that allows the cover to be manually peeled from the barrier. The reservoir holds the dermatological fluid temporarily to prevent vapors from the fluid from igniting during the barrier/cover sealing process.

RELATED APPLICATIONS

The present application is a continuation-in-part application ofApplication No. Ser. 08/789,628, dated Jan. 27, 1997 for PREWETTEDMEDICAL WIPE WITH IMPERMEABLE BARRIER in the name of Robert E. Weinsteinnow abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to wipes, more specifically, to prewetted,disposable absorbent wipes that have a barrier that is impermeable toinfectious agents.

2. The Prior Art

Applying fluidic dermatological materials, such as antiseptics, creams,ointments, and cosmetics, to intact, disrupted, or diseased skin andwiping unwanted materials from the skin are normal medical and personalhygiene procedures. This is usually done by means of an applicator,swab, or wipe (collectively, a wipe). Typically, the wipe contains onlyan amount of porous absorbent material, for example, a square or ball ofcotton. Until relatively recently, there was no satisfactory solution tothe problem of body fluids migrating from one side of the wipe to theother. The migration would occur either through the wipe or laterally onone side of the wipe and seeping over the peripheral edges to reach theopposite side of the wipe. If the person holding the wipe was not usingsome form of protection, such as rubber gloves, or the protection wasdefective, this migration exposed both the person doing the wiping andthe person being wiped to the body fluids of the other, which may becontaminated by infectious agents. Even a person applyingdermatologicals to himself or herself may be putting themselves at risk.For example, if the person uses a wipe on his diseased skin and thenrubs his eye, he may transfer an infectious agent to the eye.

A solution to the body fluid migration is suggested by the disclosure ofU.S. Pat. No. 5,009,652, issued to Morgan et al. Morgan discloses a wipewith an absorbent layer laminated to a layer that is impermeable toinfectious agents. The impermeable layer is larger in area than theabsorbent layer such that the impermeable layer extends beyond theperiphery of the absorbent layer.

Early wipes were dipped into a container of the desired fluid,immediately applied to the body, and disposed of after one use. Morerecently, in order to render the procedure more convenient and sterile,prewetted disposable wipes have been available. Prewetted wipes aremoistened with the desired fluid during the manufacturing process andsealed into a foil or foil/plastic laminate pouch. The pouch is openedto reveal the moistened wipe, used, and disposed of.

The wipe of Morgan may be used as described above, where the wipe ismoistened, used immediately, and disposed of. However, the convenienceand sterility of the packaged, prewetted wipe is lost.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a prewetted and sterilewipe that has a barrier impermeable to infectious agents.

The wetted, disposable wipe of the present invention is constructed bybonding a layer of absorbent material to one side of an impermeablebarrier, wetting the absorbent layer with a desired dermatologicalfluid, and sealing the absorbent layer so that the dermatological fluiddoes not evaporate and so that the absorbent layer maintains itssterility.

The barrier is a sheet composed of a synthetic resin film that isimpermeable to infectious agents, is not wettable by water, and isinsoluble in water, body fluids, and solutions of common antiseptics,such as isopropyl alcohol. These resin films include polyolefins andpolyvinyl copolymers. Preferred materials include those that areresistant to degradation caused by exposure to either wateroralcohol-based fluids.

If the absorbent layer is secured to the barrier such that when theperipheral edges of both are contiguous, the body fluids absorbed by theabsorbent layer can wick around the edges and reach the side of the wipethat is being held. To prevent this migration, the peripheral edges ofthe absorbent layer are spaced inwardly from the peripheral edges of thebarrier to provide a surrounding zone of the impermeable barrier alone.

Optionally, the barrier is reinforced on its periphery with a peripheralridge around the edges on one or both surfaces of the barrier. The ridgehelps to prevent the collapse of the nonwettable periphery of thebarrier, and the moat created by this ridge provides an additional trapfor body fluids.

The absorbent layer is composed of a porous material, such as gauzecotton, prepared cotton, other organic fibers such as wood fibers,rayon, open-meshed cloth of varying degrees of fineness, woven andnon-woven synthetic fibers, and foamed polymers such as polyurethane,that maintains its integrity when moistened. The absorbent layer isbonded to the barrier by techniques well known in the art of adhesives,such as heat lamination and applying a thin coat of molten polyolefin tothe barrier and pressing the absorbent layer to it before the coatsolidifies. The bond is resistant to degradation caused by exposure tothe utilized dermatological fluid.

The wetted absorbent layer is hermetically sealed into an enclosed spacebetween the barrier and a removable cover. The cover is a planar sheetthat is preferably composed of a metal foil, a plastic, or a laminate ofboth. The cover is unaffected by water and the dermatological fluidduring the shelf life of the wipe. The cover is secured to the barrierby an adhesive that is strong enough to maintain the hermetic seal, butweak enough so that the cover can be manually peeled from the barrier.The adhesive is unaffected by water and the dermatological fluid duringthe shelf life of the wipe. The preferred adhesives include alow-melting-point, toluene-treated polyolefin. Optionally, a tab extendsfrom one edge of the cover for ease in peeling the cover off.

The absorbent layer is prewetted by filling a reservoir in the barriersheet approximately in the center of the absorbent layer with thedermatological fluid prior to or after bonding the absorbent layer tothe barrier. The fluid is absorbed into the absorbent layer before thewipe is needed for use.

The wipe is held in one of several contemplated ways. In the first, theflexibility of the wipe allows a person to merely grasp the barrier,causing the wipe to crumple between the fingers, providing a handle. Inthe second, a flap extending from the barrier handle surface provides ahandle. In the third, another layer of absorbent material is bonded tothe barrier handle surface to provide a nonslip surface for grasping. Inthe fourth, the fluid reservoir can double as a handle.

Other objects of the present invention will become apparent in light ofthe following drawings and detailed description of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

For a fuller understanding of the nature and object of the presentinvention, reference is made to the accompanying drawings, wherein:

FIG. 1 is a perspective cut-away view of the wipe of the presentinvention;

FIG. 2 is a cross-sectional view of the wipe of FIG. 1; and

FIG. 3 is a perspective view of the ridge embodiment of the barrier withthe absorbent layer.

DETAILED DESCRIPTION

The wetted, disposable wipe 10 of the present invention is constructedby bonding a layer 14 of absorbent material to one side of animpermeable barrier 12, filling a reservoir 40 with a desireddermatological fluid, and sealing the absorbent layer 14 so that thefluid does not evaporate and the absorbent layer 14 maintains itssterility.

The barrier 12 is a sheet that has an absorbent layer surface 20, ahandle surface 22, a fluid reservoir 40, and four peripheral edges 24.The barrier 12 is composed of materials that are pliant and whichconform to external stresses. The barrier 12 is impervious andimpermeable to infectious agents, and is not wettable by water and isinsoluble in water, body fluids, and solutions of common dermatologicalfluids, such isopropyl alcohol.

Typical flexible, impermeable sheets are synthetic resin films. Theseresin films include polyolefins and polyvinyl copolymers, such aspolyethylene, polypropylene, polybutylene, polyvinyl acetate, polyvinylchloride, polyvinylchloride-vinylidene chloride and the like. Thechlorinated polyvinyl copolymers are highly resistant to degradationcaused by exposure to either water- or alcohol-based fluids. A barrier12 made from these materials is flexible, has strength characteristicssufficient to resist tearing and piercing under normal manufacturing andhandling stresses, is nonwettable by water, and can be sterilized andcolored. The preferred thickness of the barrier 12 is from about 0.5mils to about 15 mils, and the most preferred thickness is from about 3mils to about 8 mils.

Merely securing an impermeable barrier 12 to an absorbent layer 14 willnot necessarily prevent body fluids from migrating from one side of thewipe to the other at the peripheral edges 24. Migration can occur inboth directions, from the absorbent layer 14 to the handle surface 22 ofthe wipe, or from the person holding the wipe 10 to the absorbent layer14. The reason is that when the peripheral edges 24 of the barrier 12are contiguous with the peripheral edges 36 of the absorbent layer 14,body fluids can and will seep or wick around the peripheral edges of thebarrier and reach the opposite surface of the wipe 10. To prevent thismigration, the present invention uses an absorbent layer 14 with an areathat is smaller than that of the barrier 12. The peripheral edges 36 ofthe absorbent layer 14 are spaced inwardly from the peripheral edges 24of the barrier 12. This arrangement provides a surrounding zone 26 ofthe impermeable barrier alone, preventing the migration of body fluidsaround the peripheral edges 24 of the barrier 12. Hence, any viruses orinfectious agents that might be present in the body fluids will beconfined to only one side of the wipe 10. Consequently, the bare orglove-covered skin of a health-care worker will not contact anyinfectious agents that might be present in the body fluids of a patient.Similarly, any infectious agents from the skin of a health-care workerwill not be able to contaminate the skin of the patient. optionally, thebarrier 12 is reinforced on its periphery with a peripheral ridge 30around the edges 24 on one or both surfaces of the barrier 12, as inFIG. 3. Adding a peripheral ridge 30 to the absorbent layer surface 20of the barrier 12 creates a surrounding moat 32 between the peripheralridge 30 and the entire peripheral edge 36 of the absorbent layer 14.This moat 32 provides an additional trap so that body fluids on one sideof the wipe 10 will not migrate around edges of the barrier 12. Theperipheral ridge 30 also helps to prevent the collapse of thenonwettable periphery of the barrier 12. The thickness and width of theridge 30, however, must not be of such magnitude that the ridge 30substantially impairs the flexibility of the whole wipe 10. Preferably,the ridge 30 is also made out of a polymeric material that isnonwettable by water, impermeable to infectious agents, and insoluble inbody fluids and solutions of common dermatological fluids.

The peripheral ridge 30 is integrally formed with the underlying barrier12 in one of two ways. The ridge 30 can be created by folding up theedges of the barrier sheet or it can be formed by molding the barriersheet with a thicker edge. Alternatively, the ridge 30 is formedindependently from the underlying barrier 12 and is later bonded to thebarrier sheet. The independent ridge can be made of the same material asthe underlying barrier 12 or of a different polymeric material.Preferably, the peripheral ridge 30, also of chlorinated polyvinylcopolymers, is secured along the peripheral edges 24 of the barrier bythermal, friction, or ultrasonic means well known in the art.

Typically, a wipe 10 has overall dimensions of approximately 2 inches by2 inches, that is, the barrier 12 has dimensions of approximately 2inches by 2 inches. This is a convenient size for applying pressure orin wiping body fluids from the skin puncture or needlestick sites of apatient after the administration of an injection or a venipunctureprocedure. The absorbent layer 14 typically has overall dimensions ofabout 11/2 inches by 11/2 inches. When this size absorbent layer 14 iscentrally positioned on the barrier 12, the wipe has a surrounding zone26, consisting of the barrier alone, of about 1/4 inch. Of course, it ispossible to adopt various other sizes and shapes for the wipes, such asrectangular, circular, oval, or a combination of such shapes. Similarly,sizes and shapes of the absorbent layer 14 and its position on thebarrier 12 can vary according to use and accepted practice in themedical and hygiene arts, as long as there is a zone 26 of the barrieralone that completely surrounds the peripheral edges 36 of the absorbentlayer 14.

The absorbent layer 14 is composed of a porous material, such as gauzecotton, prepared cotton, other organic fibers such as wood fibers,rayon, open-meshed cloth of varying degrees of fineness, woven andnon-woven synthetic fibers, and foamed polymers such as polyurethane.These materials maintain their integrity when moistened. Typically, thethickness of the absorbent layer 14 ranges from about 1/64 inch to 5/8inch, depending upon the material and area of the wipe. Generally, thesmaller the area of the wipe 10, the thinner the absorbent layer 14.

The method for bonding the absorbent layer 14 to the barrier dependsupon the materials of which the barrier 12 and absorbent layer 14 aremade, and is accomplished by standard techniques well known in the artof adhesives. The bond is resistant to degradation caused by exposure tothe absorbent layer dermatological fluid. To achieve a good bond, it isa common practice to first degrease or rinse the absorbent layer surface20 of the barrier 12 by an organic solvent such as acetone or methylethyl acetone. Degreasing prepares the surface 20 for bonding.

Because the preferred absorbent materials are porous, capable ofabsorbing liquefied polymer, and allow the evaporation of vapor, most ofthe standard joining methods using adhesives with or without solventscan be used. A preferred method for joining the barrier 12 to theabsorbent layer 14 is to apply a thin coat of a molten polyolefin, suchas polyethylene, polypropylene, or polybutylene, onto the absorbentlayer surface 20 by extrusion, apply the absorbent layer 14 contiguouslyto the absorbent layer surface 20, and press them together before thecoat solidifies. Alternatively, instead of applying a thin coat ofpolyolefin by extrusion, the standard rolling technique of directgravure can be used to print the thin coat to selected areas of theabsorbent layer surface 20. Optionally, the barrier surface 34 of theabsorbent layer 14 is precoated with a polymer. The molten polyolefinabsorbed into the absorbent layer 14 will anchor to the barrier 12 and,when cooled, will bind the absorbent layer 14 and the barrier 12together.

Alternatively, the absorbent layer 14 is joined to the barrier 12 byapplying a solid powder polyolefin to the absorbent layer surface 20 ofthe barrier 12, placing the absorbent layer 14 on top of the powder, andsubjecting the two to a high-pressure heat seal.

The wetted absorbent layer 14 is sealed into an enclosed space 38between the barrier 12 and a removable cover 16. The space 38 ishermetic so that the absorbent layer 14 remains wetted anduncontaminated by external agents. The space 38 remains hermetic for anextended period of time, for example, one year. This period of timerepresents the shelf life of the wipe, which includes the period of timefrom the installation of the cover 16, through transportation andstorage, to use, when the cover 16 is removed.

The cover 16 is a planar sheet that is preferably composed of a foil ofmetal such as an aluminum alloy, a plastic, or a laminate of metal andplastic. The cover 16 is robust enough to maintain integrity while beingsubjected to normal stresses throughout transportation, storage, andhandling. The cover 16 is unaffected by water and the wettingdermatological fluid during the shelf life of the wipe 10.

The adhesive used to adhere the cover 16 to the barrier 12 is strongenough to maintain the hermetic seal, but weak enough so that a smallamount of tensional stress, such as that caused by manually peeling thecover 16 from the barrier 12, will cause the adhesive to fracture,allowing the cover 16 to be separated from the barrier 12. The adhesiveis unaffected by water and the wetting dermatological fluid during theshelf life of the wipe 10. Since there are currently no satisfactorycold sealing methods that are resistant to alcohol, a typicaldermatological fluid, the preferred adhesives include alow-melting-point, toluene-treated polyolefin. For a polyolefin, a lowmelting point is in the range of from approximately 220°-260° F.Consequently, heat must be applied to the adhesive so that the adhesivecan be applied to the barrier and/or cover when installing the cover.

Optionally, there is a tab extending from one edge of the cover 16 thatcan be grasped between a thumb and finger for ease and convenience inremoving the cover 16 from the barrier 12.

One aspect of the wipe 10 of the present invention is that the absorbentlayer 14 is prewetted, that is, it is already wetted when opened by theperson using the wipe 10. As discussed above, temperatures in the rangeof 220°-260° F. are needed to seal the cover 16 to the barrier 12.Alcohol, a common dermatological fluid used to wet the absorbent layer,has a very low flash point, the temperature at which the fluid gives offenough vapor to become ignitable. The flash point of isopropyl alcoholis 53° F. and that of ethyl alcohol is 55° F., classifying the fluids asflammable and requiring precautions. Consequently, without precautions,the act of sealing the cover to the barrier has the potential to causethe alcohol vapor to ignite.

The present invention greatly reduces the ignition problem bytemporarily storing the wetting fluid 42 in a reservoir 40 while thebarrier 12 and cover 16 are being sealed together. The reservoir 40 is apouch formed in the barrier sheet 12 and centered approximately in thecenter of the absorbent layer 14. The reservoir 40 is filled with thedermatological fluid 42 either prior to or after the absorbent layer 14is bonded to the barrier 12. If filled after, the dermatological fluid42 is injected into the reservoir 40 through the absorbent layer 14using, for example, a syringe or similar device. The barrier 12 andcover 16 should be sealed together relatively quickly after thereservoir 40 is filled. With contact between the dermatological fluid 42and the absorbent layer 14 occurring as the wipe 10 is moved, thedermatological fluid 42 will definitely be absorbed into the absorbentlayer 14 before the wipe 10 is needed for use.

The wipe 10 is held by a person on the handle surface 22 of the barrier12. There are several contemplated alternatives in which a handle isprovided. In the first, the flexibility of the wipe 10 allows a personto merely grasp the barrier, causing the wipe 10 to crumple between thefingers and providing a handle. In the second alternative, a flapextending from the barrier handle surface 22 provides a handle. In thethird alternative, another layer of absorbent material is bonded to thebarrier handle surface 22. This "grasping layer" is not prewetted andprovides a nonslip surface for grasping. In the fourth alternative, thereservoir pouch extending away from the handle surface 22 is used as ahandle. If the pouch is flexible, the material of the empty pouch isbunched together in the center of the barrier to form a handle. If thepouch is somewhat rigid, the outer surface of the pouch may textured toprovide a non-slip surface.

Thus it has been shown and described a prewetted, disposable wipe whichsatisfies the objects set forth above.

Since certain changes may be made in the present disclosure withoutdeparting from the scope of the present invention, it is intended thatall matter described in the foregoing specification and shown in theaccompanying drawings be interpreted as illustrative and not in alimiting sense.

What is claimed is:
 1. A wipe comprising:a. a barrier composed of asheet that is impermeable to infectious agents and having a surroundingperipheral edge; b. an absorbent layer secured to said barrier andhaving a surrounding peripheral edge and a prewetted area smaller thansaid barrier; c. a reservoir in said barrier adjacent to said absorbentlayer, said reservoir being filled with a dermatological fluid that issubsequently absorbed by said absorbent layer prior to use; d. absorbentlayer securing means for securing said absorbent layer to said barrier,said absorbent layer being located on said barrier such that saidabsorbent layer peripheral edge is spaced inwardly from said barrierperipheral edge, providing a zone of said barrier surrounding saidabsorbent layer; e. a cover composed of a thin, flexible sheet havingapproximately the same shape and area as said barrier; and f. coversecuring means for securing said cover to said barrier zone such thatsaid absorbent layer is contained within a hermetically closed spacebetween said barrier and said cover, said cover securing means includingthe use of heat that has a temperature higher than the flash point ofsaid dermatological fluid, said cover securing means having a tensionalstress resistance that permits manual removable of said cover from saidbarrier.
 2. The wipe of claim 1 wherein said absorbent layer securingmeans is resistant to degradation by said dermatological fluid for atleast a predetermined period of time.
 3. The wipe of claim 1 whereinsaid absorbent layer securing means is a polyolefin adhesive.
 4. Thewipe of claim 1 wherein said cover securing means is resistant todegradation by said dermatological fluid for at least a predeterminedperiod of time.
 5. The wipe of claim 1 wherein said cover securing meansis an adhesive composed substantially of a low-melting-point,toluene-treated polyolefin.
 6. The wipe of claim 1 wherein said barrierzone includes a peripheral ridge rising from said barrier zone surface.7. A wipe comprising:a. a barrier composed of a sheet that isimpermeable to infectious agents and having a surrounding peripheraledge; b. an absorbent layer secured to said barrier and having asurrounding peripheral edge and a prewetted area smaller than saidbarrier; c. a reservoir in said barrier adjacent to said absorbentlayer, said reservoir being filled with a dermatological fluid that issubsequently absorbed by said absorbent layer prior to use; d. absorbentlayer securing means for securing said absorbent layer to said barrier,said absorbent layer being located on said barrier such that saidabsorbent layer peripheral edge is spaced inwardly from said barrierperipheral edge, providing a zone of said barrier surrounding saidabsorbent layer, said absorbent layer securing means being resistant todegradation by said dermatological fluid for at least a predeterminedperiod of time; e. a cover composed of a thin, flexible sheet havingapproximately the same shape and area as said barrier; and f. coversecuring means for securing said cover to said barrier zone such thatsaid absorbent layer is contained within a hermetically closed spacebetween said barrier and said cover, said cover securing means includingthe use of heat having a temperature higher than the flash point of saiddermatological fluid, said cover securing means having a tensionalstress resistance that permits manual removable of said cover from saidbarrier, said cover securing means being resistant to degradation bysaid dermatological fluid for at least a predetermined period of time.8. The wipe of claim 7 wherein said absorbent layer securing means is apolyolefin adhesive.
 9. The wipe of claim 7 wherein said cover securingmeans is an adhesive composed substantially of a low-melting-point,toluene-treated polyolefin.
 10. The wipe of claim 7 wherein said barrierzone includes a peripheral ridge rising from said barrier zone surface.11. A wipe comprising:a. a barrier composed of a sheet that isimpermeable to infectious agents and having a surrounding peripheraledge; b. an absorbent layer secured to said barrier and having asurrounding peripheral edge and a prewetted area smaller than saidbarrier; c. a reservoir in said barrier adjacent to said absorbentlayer, said reservoir being filled with a dermatological fluid that issubsequently absorbed by said absorbent layer prior to use; d. apolyolefin absorbent layer adhesive for securing said absorbent layer tosaid barrier, said absorbent layer being located on said barrier suchthat said absorbent layer peripheral edge is spaced inwardly from saidbarrier peripheral edge, providing a zone of said barrier surroundingsaid absorbent layer, said absorbent layer adhesive being resistant todegradation by said dermatological fluid for at least a predeterminedperiod of time; e. a cover composed of a thin, flexible sheet havingapproximately the same shape and area as said barrier; and f. alow-melting-point, toluene-treated polyolefin cover adhesive forsecuring said cover to said barrier zone such that said absorbent layeris contained within a hermetically closed space between said barrier andsaid cover, said cover adhesive needing heat in order to apply saidcover adhesive to secure said cover to said barrier zone, said heathaving a temperature higher than the flash point of said dermatologicalfluid said cover adhesive having a tensional stress resistance thatpermits manual removable of said cover from said barrier, said coveradhesive being resistant to degradation by said dermatological fluid forat least a predetermined period of time.
 12. The wipe of claim 11wherein said barrier zone includes a peripheral ridge rising from saidbarrier zone surface.